Insurance Premiums and Service Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Insurance Premiums and Service Revenue [Abstract]
Direct Premiums Written	$ 438	$ 491	$ 420
Direct Premiums Earned	429	464	414
Assumed Premiums Written	3	0	0
Assumed Premiums Earned	3	2	4
Premiums Written, Gross	441	491	420
Premiums Earned, Gross	432	466	418
Ceded Premiums Written	(211)	(232)	(219)
Ceded Premiums Earned	(208)	(209)	(197)
Premiums Written, Net	230	259	201
Premiums Earned, Net	224	257	221
Service Revenue Written	999	1,051	973
Service Revenue Earned	879	830	801
Insurance Premiums and Service Revenue Written	1,229	1,310	1,174
Insurance premiums and service revenue earned	$ 1,103	$ 1,087	$ 1,022